This invention relates to ornamental and protective edge guards which are applied to the edges of body panels commonly used in automotive vehicle bodies, such as the vehicle door edges.
In a typical automotive vehicle door edge guards are applied to trailing edges of the vehicle's doors to protect the door edges from damage which might be caused by striking an object which may be present in a door's path when the door is opened. It is very desirable for such door edge guards to be made of bright metal, such as stainless steel, aluminum, or bi-metal, due to the superior protective and ornamental characteristics of such materials. Furthermore, the inherent strength and resiliency of such metallic edge guards enable them to be self-retaining on the doors. Correspondingly, it is generally undesirable to use separate fasteners or adhesive in securing edge guards to doors since they involve extra cost in labor and materials. It is also generally undesirable to use non-metallic edge guards, such as vinyl edge guards, since they do not possess the superior protective, ornamental, and self-retention characteristics of the bright metallic edge guards. In connection with the use of self-retaining edge guards, it has heretofore been recognized that the potential for paint scratching and marring exists when the metallic edge guards are applied to vehicle doors. Such paint scratching can lead to premature corrosion of the door edge metal. Some of applicant's own inventions have addressed the paint scratching problem and provided solutions. For example reference is made to U.S. Pat. Nos. 4,259,812; 4,334,700; 4,316,348 and to pending application Nos. 194,748; 194,747; 194,749; 216,483; 216,860; 205,419; 205,420; 323,510; 323,513; 323,512; 323,511; 369,332. Certain of these patents and pending applications disclose the use of plastic liners to insulate the metallic edge guard from the door edge. From the standpoint of ease of installation on a door edge, the most desirable construction is to provide the liner as an integral laminate to the metallic edge guard channel. In accordance with procedures invented by applicant one way of providing this construction is by laminating plastic film to sheet metal material and then roll forming the laminate to the desired cross sectional shape.
Several of the above mentioned patents and pending patent applications disclose edge guard constructions in which a portion of the insulating material is visible on the exterior of the edge guard installed on a vehicle door. For example the visible insulating material comprises a thin band running lengthwise of the metal strip at the distal end of the bead of the outer leg of the U-shaped cross section of the channel which applies the self-retention force against the outside of the door edge. The present invention in certain respects represents an improvement upon an edge guard of this type in which a portion of the liner is exposed to view. From the standpoint of economy and manufacturing, plastic films of polyvinylchloride are deemed particularly advantageous. The polyvinylchloride film can be readily bonded to the metal which forms the edge guard channel section and it provides suitable insulating characteristics. One problem which has been noted by applicant in connection with polyvinylchloride film is that lighter colored versions of such film are susceptible to color change due to environmental factors. This means that the color range which is commercially acceptable must comprise darker colors such as black, dark brown, or navy. This limited color range may not be accepted for all styling requirements for automotive vehicles with which the edge guards are to be used. Lighter colored polyvinylchloride films tend to discolor with age, being attacked by ozone, moisture, ultra-violet radiation, salt air, exposure to extreme heat and cold, detergents, oil, etc.
The present invention is directed to a new and improved insulated edge guard which possesses the advantages of polyvinylchloride film, yet which also provides for color appearances which are not limited to the darker shades referred to above and which are highly resistant to discoloration due to the factors also mentioned above. With the invention, a versatility is imparted to commercially acceptable performance requirements for an insulated edge guard. The color appearance of the insulation may be chosen to match the color of the bright metal of the edge guard. Alternatively the color may be chosen to match that of the painted body panel on an edge portion of which the edge guard is disposed. Still another possibility is that the color may be different from both the painted body panel and the exterior of the metal channel. With the first two possibilities the appearance of the insulated edge guard channel is rendered virtually like that of uninsulated edge guards in which the appearance is that of a bright metal strip running along the edge on which it is disposed.
The preferred embodiment of the invention comprises for the insulating liner superimposed layers of film. The inner film is a polyvinylchloride film which is readily adhered to the metal of the edge guard channel by procedures described in other of applicant's patents and patent applications. The other is an outer film of polyvinylfluoride which is bonded to the polyvinylchloride film by conventional procedures. Polyvinylfluoride is itself not directly readily bondable to the metal of the edge guard channel, yet it does bond to the polyvinylchloride. Unlike the polyvinylchloride, the lighter colors of polyvinylfluoride do not experience the discoloration problem. Hence the invention achieves a significant improvement in an edge guard of the type described.
The foregoing features, advantages and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawing. The drawing discloses a preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.